Matthew 19:8

πρὸς τὴν σκληροκαρδίαν ὑμῶν. Having respect to, with a view to the hardness of your hearts towards God. So the law was relatively good, not absolutely. A great principle. Even now all are not capable of the higher religious life or of the deepest truths. Some interpret ‘hardness of heart,’ of the cruelty of men towards their wives.

ἐπέτρεψεν, ‘allowed,’ a correction of ἐνετείλατο, Matthew 19:7. Moses did not enjoin, but merely permitted a bill of divorce.

οὐ γέγονεν. Not ‘was not so,’ A.V., but ‘hath not been so’ continuously from the beginning to the present time. It is not an original and continuous tradition.